Adjustable pitch propeller



Nov. 15, i949 F. w. TURNBULL DJUSTABLE FITCH PROPELLER 3 Sheets-Sheet l Filed Oct. 10, 1945 ON N Nm l m fo FREDERICK W. TURNBULL ,y l5, i949 F. w. TURNBULL 2,487,836

ADJUSTABLE FITCH PROPELLER 3 1 vu ank-M FREDERiCK W. TURNBULL Nw., 15, 394 v F. w. TURNBULL 2,487,836

ADJUSTABLE FITCH PROPELLER Filed Oct. 10, 1945 3 Sheets-Sheet 3 PEG., E

FREDERGK W. TURNBULL which passes an inner shaft and Patented Nov. 15,h 1949 s PATENT OFFICE VADJUSTABLE PITCH PROPELLER Y, Frederick W. Turnbull, Vienna, Va. Application October 10, 1945, Serial No. 621,632 12 Claims. (Cl.170160.3) (Granted lunder the act of March 3,- 188s, as

This invenion relates to an adjustable pitch propeller with suitable controls associated therewith, and more particularly to a propeller of the screw type having blades which are rotatably adjustable as desired for altering the pitch thereof,

as well as for completely'reversing the pitch ofv the blades for obtaining astern motion of a vessel.

According to the improvements set forth herein, a propeller hub is illustrated which is driven by means of a hollow propeller shaft through within which said inner shaft is suitably mounted. The inner vshaft is so associated with the propeller shaft that it rotates therewith during normal operation, but is adapted to be, by means of a suitable source of power, rotated relatively to said propeller shaft when required for blade adjustment and release of the propeller blade clutch.

With the blade or blades there is included a control flap portion, which flap is y mounted preferably along and forming part of the trailing edge of the blade. The flap portion is controlled and actuated by means of the inner shaft and a system of connected gears associated therewith, As soon as the flap has been adjusted to the de- Ysired position, a clutch associated with each propeller blade is released to allow the opposing reaction caused by the water through which each blade and control flap are moving to cause the blades to be moved to their predetermined final position. The lag between the setting of the flap and the clutch release is conveniently accomplished by means of a lost motion or back-lash device in the gearing system. After the adjustment has been accomplished as outlined,- the clutch reengageswith the base of the bladeY to secure the blade in the final adjusted position.

From the above description it is apparent that the clutch does not release the blade for moveyment until the maximum torque is exerted by the ilap. Retrogression of the blade to its original position can only be accomplished by the reverslng of the flap and blade controlling mechanism, which first sets the ap to produce a retrogressing torque, then releases the clutch in the opposite sense from the release action described above.

Although the control flap portion, the clutch and the blade are illustrated as a compact unit, it will be appreciated that they may be operated independently of each other.

In addition to being adapted to release the clutch, it will be noted that the gearing will positively and independently rotate the blade where .Y amended-April 30, 1928; 370 0. G. 757) substantial adjustment thereof is required.,v shown in the illustrated embodiment@ relatively simple and ruggedmechanical adjusting means is provided. Further, it is to be appreciatedthat the substitution of hydraulic, pneumatic or electric drives are contemplated to be withinY the scope of the improvements as described and claimed herein. A positively controlled adjustable pitch propeller is herein provided which may be released so that proper adjustment thereof from the controls of the ship can be made in accordance with any desired plan. I f

As illustrated in a, prior patent issued toA.v Flettner, Number 1,556,012 and dated October'l, 1925, the use of flaps or governing surfaces, which when disposed at an angle to the blade surface will cause the current flowing along the blagde to exert pressures differing from one another, is known. It is stated in the patent that this reaction will cause the blade to be turned yuntil it has adjusted itself to the position of equilibrium corresponding to the direction of rotation andto the number of revolutions which may be made by this screw in each individual case. Unlike the present invention, the propeller of the patent is free at all times thereby subjecting it to a huntingaction causing departure and adjusting procedure to take place constantly. y

An Object of this invention is to provide an adpitch to which the propeller is subjected is adjusted by a ap portion mounted on the propeller blade or by positive driving means, or by the one in aid of the other. A

Another object is to provide a current responsive propeller adjusting member which can be set in any one of aninvfinite number of predetermined positions, such adjustment being made from inside of the vessel on which it ismounterd. A further object of the invention is to provide a propeller blade clutch mechanism and means p associated therewith for positively driving the propeller blades to adjust the pitch, V'

These, as well as the various other novel features and advantages ofv this invention will become apparent vfrom a reading of the specification and accompanying drawings of which:

Figure 1 isa side elevational view, with parts broken away, showing the arrangement ofthe drive, clutch and propeller'blades, y l

FigureZ is an end 'view of the propeller hub having one blade mounted therein and a control flap associated therewith. v

I Figure Sis a `plan view, partly-in section, ofthe 551 clutch for securing the blade. .f

justable pitch propeller in which the amount of Figures 4 through 11 are diagrammatic views of a cross section of the propeller blade showing the various steps attained during adjustment.

With respect to the drawings, Figures 1 and 2 illustrate a propeller shaft I Il adapted to be driven in a clockwise or counter-clockwise direction through gear II from a primary source of power (not shown). Shaft I is made for the sake of illustration integral with its hub portion I 2 within which are rotatably mounted adjustable propeller blades I3. A reversing motor such as 'direct current motor I4 and shaft I5 rotates bodily with shaft Ill, four slip rings I6 through I9 of motor I4 are connected for sliding contact with brushes 20 through 23 respectively, and the direction of rotation of the motor is determined by having secured to the leads a switch mechanism and source of power (not shown).

The motor shaft I is provided with a gear 24 keyed thereto for driving the. inner shaft 25,

and 21. Suitable bearings 28 and 2S are spaced along the shaft I6 to support the inner shaft 25. Y

`A portion at the end of shaft has mounted thereon gears and 3I, which gears engage cooperating bevel gears 32 and 33 of the propeller blade I 3.` A slot 34 provided on gear 3i! engages a projection 35 of. shaft 25. This combination of Vslot and projection constitutes a lost motion o1' back-lash device as will be more fully explained hereinafter. In normal operation of a ship, as a huh portion I2 and blades I3 are turned, there -will be no driving or relative motion between sets of gears 3U-32and 3I-33.

For securing the propeller blades I3 to the hub, plates 36 are provided which plates in turn are fastened to the hub by screws 3l. All blades as illustrated are similarly mounted and driven..

like numerals being given to like parts thereof. It is to be understood that two, three, four or more blades as desired may be employed in combination with the invention described herein.

vIn accordance with Fig. 1 gears 36 and 3l are constantly in engagement with gears 32 and 33,

respectively When the motor I4 is actuated,

gear 3| causes gear 33 to be driven` so that the control ap 38 is operated through a flexible cable l 39. Cable 39 is secured at one end to gear 4U, en-

leasing the elements so that the desired adjustment canbe completed. This disengagement is accomplished in the illustrated embodiment by projection 35 turning gear 30, which in turn operates gear 32. The projections 46 or 4'I, mounted on gear. 32 push one of each set of balls 48 in the direction of rotation. The other ball is pushed i in the direction of rotation by spring'SI.

With reference to Figure 3, it will be seen that .the gear 30 may be used as an aid for adjusting the flap or for making the desired adjustment of the blade independently of the ilap. The clutch illustrated is a simple type and yet most effective in operation. The housing for the clutch is an- .,nular and contains the ball members 48 and spring 5I which wedge the balls between the housing and cam surfaces on the stub of the y blade. The housing is formed by the hub and the propeller stub end. There are several pairs of 1 projections 46and 4l on gear 32 which protrude into the clutch housing. Movement of the gear Yvice connected to said gear whereby ciu 'prevents the driven member being turned backward with relation to the driving member, since the ball elements, which are not held disengaged by the driving element, are kept constantly in place by spring 5I to prevent such movement by wedging between the hub and the stub of the blade. It is also to be noted that the driven element can progress only at the same speed as the driving element. More rapid movement will release the ball from the disengaging forcev and it will be pressed into clutching position by spring 5I so that the balls are wedged between the hub and the blade stub. i

In accordance with Figures 4 through 7, the hub is illustrated as being driven in a clockwise direction when viewed from the left. The blade rotating with the hub is rst shown as having no pitch whatsoever. In Figure 5, a. control flap is illustrated as having been rotated out of line with the propeller blade edge. This places a clockwise twist on the blade when viewed toward the hub. If the clutch is released, the'blade will tend to progress to the position shown in Figure 6, when the clutch is again engaged to secure the blade in the adjusted position. Thereupon thev control flap is returned into alignment Vwiththe blade so that the vessel will be propelled in an astern direction.

When the propeller is not in rotation, adjust ment of the blade will be had by the cooperating action of the gears 30 and 32 together with the clutch 45. l

Also as illustrated in Figures 8 through 1l when the blade is Yin a certain position, the control will have little or no adjusting effect. In such cases adjustment will be made independently of the flap as above described. When the propeller is employed with `a Yreversing engine, the blades may be rotated for affecting astern motion thereby presenting a propeller having thesame identical characteristics which are inherent in the propeller when motion is in a forward direction.

The invention described herein may be made and used by or for the Government ofthe United States for governmental purposes without the payment to me of any royalties thereon or therefor.

What is claimed is: v y

1. An adjustable pitch propeller comprising-a drive shaft, a hub secured to said shaft; a propeller blade rotatably supported by said hub, a clutch within said hub betweensaidmaae and hub, and a gear rotatably mounted onfslid blade for driving said propeller blade thro said clutch, said clutch comprising aV runway fo ned by the converging walls of the blade and a ball movable in said runway, a spring normally urging said -ball into wedged contact with said converging runway walls, and a `ball relearip demay be released and said blade rotated 'relative to saidrhub. Y f j j 2. An adjustable pitch propeller comprising a drive shaft having a. propeller hub', a propeller blade supported within and adapted to be rotated relative to said hub, a control ap adjustablj7 secured to said blade, means to adjust the flap and a clutch operated by the ap adjusting means fol locking and releasing said blade With relation to said hub.

3. An adjustable pitch propeller comprising a drive shaft having a propeller hub, a propeller blade supported Within and adapted to be rotated relative to said hub, a control flap adjustably secured to said blade, actuating means for adjusting said flap and for rotating said propeller blade to augment the action of said control flap, said actuation means including a clutch for locking and releasing said blade with relation to said hub.

4. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a propeller blade adjustably supported by said hub, a control iiap secured to said propeller blade, a clutch for looking and releasing said blade with respect to said hub, means for rotating said flap to a predetermined position relative to said blade, said last mentioned means including a single drive shaft adapted to actuate said clutch as desired.

5. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a propeller blade adjustably supported by said hub, a clutch Within said hub for locking said propeller blade to said hub, means independent of such 1 clutch to produce an adjusting force o-n said propeller blade, and control means, comprising means for positively rotating said propeller blades relatively to said hub and actuating said blade force adjusting means.

6. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a propeller blade adjustably supported by said hub, a clutch operable in either direction within said hub for locking said propeller blade to said hub,

means to produce a primary adjusting force on said propeller blade, means to release said clutch, said releasing means providing a secondary adjusting force to aid in adjusting said blade, and single means for actuating both said primary and secondary force adjusting means.

7. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a propeller blade adjustably supported by said hub, means utilizing the action of the medium in which propeller is operating to exert an adjusting torque on said blade, a clutch for locking and releasing said blade with respect to said hub and a common driving element to actuate both said means and release said clutch in sequence.

8. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a propeller blade adjustably supported by said hub, a clutch within said hub for locking said propeller blade to said hub, clutch control means comprising means for positively rotating said propeller blade relatively to said hub and additional means operated 'by said clutch control means, for prestressing the blade With a torque, to aid in adjusting said blade.

9. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a plurality of propeller blades adjustably supported by said hub, means utilizing the action of the medium in which the propeller is operating to exert an adjusting torque on each of said blades, a clutch mounted on each blade for locking and releasing said blades with respect to said hub and a common driving element to actuate said means and said clutches as desired.

10. The device in claim 9 in which the said driving element comprises means interconnecting all of the blades so that each blade is adjusted at the same pitch angle as all of the other blades.

11. An adjustable pitch propeller comprising a drive shaft, a hub secured to said shaft, a propeller blade supported for rotation relative to said hub, a clutch Within said hub between said hub and the root of said blade, releasably holding said blade against said rotation, and clutch operating means rotatably mounted on said blade for driving said propeller blade through said clutch.

12. An adjustable pitch propeller comprising a hub, a propeller blade rotatably supported by said hub, a driving means rotatably mounted on said blade for rotating said blade with respect to said hub, and a device to clutch said hub to said blade and to rotate said blade in said hub, selectively operable in either direction by rotation of the driving means with respect to the blade to adjust the pitch of said blade.

FREDERICK W. TURNBULL.

REFERENCES CITED The following references are of record in the file of this patent:

UNTTED STATES PATENTS Number Name Date 449,888 Shepperd Apr. 7, 1891 997,819 Holmes July 11, 1911 1,556,012 Flettner Oct.`6, 1925 1,668,971 McCauley May 8, 1928 1,833,843 Leparmentier Nov. 24, 1931 1,891,272 Slorfimsky Dec. 20, 1932 1,917,965 Gerhardt July 11, 1933 1,964,102 Wishon June 26, 1934 2,156,102 Austin Apr. 25, 1939 2,208,602 Rutl'ls et a1 July 23, 1940 2,276,347 Ruths et al Mar. 17, 1942 2,309,899 Hepperte Feb. 2, 1943 2,360,932 Sahle Oct. 24, 1944 2,370,135 Berliner Feb. 27, 1945 2,392,364 Caldwell et al Jan. 8, 1946 2,403,532 Hoover July 9, 1946 FOREIGN PATENTS Number Country Date 52 Great Britain 1907 19,505 Great Britain 1904 95,613 Sweden Mar. 2, 1939 373,492 Italy 1939 

